Guys, before we start thinking of replacing CPC solenoids and CP switches as a "cure all", let's just stand back and take a look at the overall situation.
CPC solenoids and CP swtiches greatly affect the driveability (not reliability) of any transmission, whether it be the 1999-2001 Odyssey 4-speed, or the 2002-2004 Ody 5-speed. If they work properly, the transmission will operate properly if the internals are mechanically sound.
My A/T's are still working fine, but when they hit the point where they don't, these will be the first items I check...basic electric sensors (clutch pressure switches) and electrically actuated fluid control pieces (clutch pressure control solenoids). Like any switch or solenoid, they have a certain number of cycles they can endure before they reach their MTBF (mean time between failure) or MCBF (mean cycle between failure) points.
Of course, if you don't address the operability issues in the short term, they can affect long-term reliability.
This thread is about a 2000 Odyssey. Completely different from the 3rd Gen TL 5-speed in dannyz's post (and his 2004 Ody) in terms of most often-seen failure modes, but alike with the BYBA-coded 2002-2004 5-speed. Also, if his 2004 is a 5FNRL18xx4B051621 or later VIN, odds are that all 3rd clutch ATF flow restrictions were fixed in production and the 2nd gear oil jet mod was incorporated internally as well.
BYBA and similarly-cored 5-speed Honda A/T's did not mechanically fail due to electrical switching and fluid power transmission logic snafus. They primarily failed because of three NHTSA-identified mechanical ATF flow restrictions to the third clutch.
I still have the enormous NHTSA report in .pdf format for anybody who wants it. Send me a PM with an email addy, but beware...it's huge. No guarantees it won't crash an email server.
The NHTSA did not identify the high-silicone-base Honda ATF-Z1 as causing 5-speed 3rd clutch failures...that said, I'm not a fan of such an old ATF spec originally designed for Hondamatic A/T's in small vehicles now being used in much heavier vehicles with much more powerful engines. That's why I now use a quality synthetic ATF. Less friction modifiers and firmer shifts? Yup. Longer clutch pack life? Most likely.